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authorChristian Gromm <christian.gromm@microchip.com>2015-09-28 15:18:45 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-09-29 01:18:51 (GMT)
commit71457d482751a38e78da32fde80e87b6f670c389 (patch)
tree5a5c845fb2a78d9c33ee48b1448473316af73cfa
parentc81c9c3e0fd5170e7bede7d06202062338644e93 (diff)
downloadlinux-71457d482751a38e78da32fde80e87b6f670c389.tar.xz
staging: most: add fair buffer distribution
This patch ensures a fair distribution of buffers, when two AIMs share a single channel. The AIMs then won't be able to use more than half of all pre-allocated buffers of the linked channel. However, in case the channel is not shared, the AIM can exclusively use all available buffers. Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de> Signed-off-by: Christian Gromm <christian.gromm@microchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/staging/most/aim-cdev/cdev.c5
-rw-r--r--drivers/staging/most/aim-network/networking.c2
-rw-r--r--drivers/staging/most/aim-sound/sound.c3
-rw-r--r--drivers/staging/most/hdm-dim2/dim2_hdm.c2
-rw-r--r--drivers/staging/most/mostcore/core.c27
-rw-r--r--drivers/staging/most/mostcore/mostcore.h4
6 files changed, 36 insertions, 7 deletions
diff --git a/drivers/staging/most/aim-cdev/cdev.c b/drivers/staging/most/aim-cdev/cdev.c
index a8a7689..23c3f6e 100644
--- a/drivers/staging/most/aim-cdev/cdev.c
+++ b/drivers/staging/most/aim-cdev/cdev.c
@@ -165,7 +165,7 @@ static ssize_t aim_write(struct file *filp, const char __user *buf,
}
mutex_unlock(&channel->io_mutex);
- mbo = most_get_mbo(channel->iface, channel->channel_id);
+ mbo = most_get_mbo(channel->iface, channel->channel_id, &cdev_aim);
if (!mbo) {
if ((filp->f_flags & O_NONBLOCK))
@@ -173,7 +173,8 @@ static ssize_t aim_write(struct file *filp, const char __user *buf,
if (wait_event_interruptible(
channel->wq,
(mbo = most_get_mbo(channel->iface,
- channel->channel_id)) ||
+ channel->channel_id,
+ &cdev_aim)) ||
(!channel->dev)))
return -ERESTARTSYS;
}
diff --git a/drivers/staging/most/aim-network/networking.c b/drivers/staging/most/aim-network/networking.c
index c13bd89..f0d9a43 100644
--- a/drivers/staging/most/aim-network/networking.c
+++ b/drivers/staging/most/aim-network/networking.c
@@ -245,7 +245,7 @@ static netdev_tx_t most_nd_start_xmit(struct sk_buff *skb,
BUG_ON(nd->dev != dev);
- mbo = most_get_mbo(nd->iface, nd->tx.ch_id);
+ mbo = most_get_mbo(nd->iface, nd->tx.ch_id, &aim);
if (!mbo) {
netif_stop_queue(dev);
diff --git a/drivers/staging/most/aim-sound/sound.c b/drivers/staging/most/aim-sound/sound.c
index 2d4732c..0d7425b 100644
--- a/drivers/staging/most/aim-sound/sound.c
+++ b/drivers/staging/most/aim-sound/sound.c
@@ -251,7 +251,8 @@ static int playback_thread(void *data)
wait_event_interruptible(
channel->playback_waitq,
kthread_should_stop() ||
- (mbo = most_get_mbo(channel->iface, channel->id)));
+ (mbo = most_get_mbo(channel->iface, channel->id,
+ &audio_aim)));
if (!mbo)
continue;
diff --git a/drivers/staging/most/hdm-dim2/dim2_hdm.c b/drivers/staging/most/hdm-dim2/dim2_hdm.c
index 4481a0b..1bb70b7 100644
--- a/drivers/staging/most/hdm-dim2/dim2_hdm.c
+++ b/drivers/staging/most/hdm-dim2/dim2_hdm.c
@@ -669,7 +669,7 @@ static void request_netinfo(struct most_interface *most_iface, int ch_idx)
return;
}
- mbo = most_get_mbo(&dev->most_iface, dev->atx_idx);
+ mbo = most_get_mbo(&dev->most_iface, dev->atx_idx, NULL);
if (!mbo)
return;
diff --git a/drivers/staging/most/mostcore/core.c b/drivers/staging/most/mostcore/core.c
index 0053b8c..4dfa001 100644
--- a/drivers/staging/most/mostcore/core.c
+++ b/drivers/staging/most/mostcore/core.c
@@ -36,6 +36,7 @@ static struct class *most_class;
static struct device *class_glue_dir;
static struct ida mdev_id;
static int modref;
+static int dummy_num_buffers;
struct most_c_obj {
struct kobject kobj;
@@ -59,6 +60,8 @@ struct most_c_obj {
struct most_aim *second_aim;
int first_aim_refs;
int second_aim_refs;
+ int first_num_buffers;
+ int second_num_buffers;
struct list_head trash_fifo;
struct task_struct *hdm_enqueue_task;
struct mutex stop_task_mutex;
@@ -1233,6 +1236,7 @@ static void arm_mbo(struct mbo *mbo)
}
spin_lock_irqsave(&c->fifo_lock, flags);
+ ++*mbo->num_buffers_ptr;
list_add_tail(&mbo->list, &c->fifo);
spin_unlock_irqrestore(&c->fifo_lock, flags);
@@ -1286,6 +1290,7 @@ static int arm_mbo_chain(struct most_c_obj *c, int dir,
goto _error1;
}
mbo->complete = compl;
+ mbo->num_buffers_ptr = &dummy_num_buffers;
if (dir == MOST_CH_RX) {
nq_hdm_mbo(mbo);
atomic_inc(&c->mbo_nq_level);
@@ -1384,22 +1389,40 @@ most_c_obj *get_channel_by_iface(struct most_interface *iface, int id)
* This attempts to get a free buffer out of the channel fifo.
* Returns a pointer to MBO on success or NULL otherwise.
*/
-struct mbo *most_get_mbo(struct most_interface *iface, int id)
+struct mbo *most_get_mbo(struct most_interface *iface, int id,
+ struct most_aim *aim)
{
struct mbo *mbo;
struct most_c_obj *c;
unsigned long flags;
+ int *num_buffers_ptr;
c = get_channel_by_iface(iface, id);
if (unlikely(!c))
return NULL;
+
+ if (c->first_aim_refs && c->second_aim_refs &&
+ ((aim == c->first_aim && c->first_num_buffers <= 0) ||
+ (aim == c->second_aim && c->second_num_buffers <= 0)))
+ return NULL;
+
+ if (aim == c->first_aim)
+ num_buffers_ptr = &c->first_num_buffers;
+ else if (aim == c->second_aim)
+ num_buffers_ptr = &c->second_num_buffers;
+ else
+ num_buffers_ptr = &dummy_num_buffers;
+
spin_lock_irqsave(&c->fifo_lock, flags);
if (list_empty(&c->fifo)) {
spin_unlock_irqrestore(&c->fifo_lock, flags);
return NULL;
}
mbo = list_pop_mbo(&c->fifo);
+ --*num_buffers_ptr;
spin_unlock_irqrestore(&c->fifo_lock, flags);
+
+ mbo->num_buffers_ptr = num_buffers_ptr;
mbo->buffer_length = c->cfg.buffer_size;
return mbo;
}
@@ -1530,6 +1553,8 @@ int most_start_channel(struct most_interface *iface, int id,
goto error;
c->is_starving = 0;
+ c->first_num_buffers = c->cfg.num_buffers / 2;
+ c->second_num_buffers = c->cfg.num_buffers - c->first_num_buffers;
atomic_set(&c->mbo_ref, num_buffer);
out:
diff --git a/drivers/staging/most/mostcore/mostcore.h b/drivers/staging/most/mostcore/mostcore.h
index e23ad7c..3c6fb19 100644
--- a/drivers/staging/most/mostcore/mostcore.h
+++ b/drivers/staging/most/mostcore/mostcore.h
@@ -190,6 +190,7 @@ struct mbo {
void *priv;
struct list_head list;
struct most_interface *ifp;
+ int *num_buffers_ptr;
u16 hdm_channel_id;
void *virt_address;
dma_addr_t bus_address;
@@ -307,7 +308,8 @@ void most_stop_enqueue(struct most_interface *iface, int channel_idx);
void most_resume_enqueue(struct most_interface *iface, int channel_idx);
int most_register_aim(struct most_aim *aim);
int most_deregister_aim(struct most_aim *aim);
-struct mbo *most_get_mbo(struct most_interface *iface, int channel_idx);
+struct mbo *most_get_mbo(struct most_interface *iface, int channel_idx,
+ struct most_aim *);
void most_put_mbo(struct mbo *mbo);
int most_start_channel(struct most_interface *iface, int channel_idx,
struct most_aim *);